Some students have difficulty trusting classmates outside their circle. Parents say interactions with school staff are more impersonal. Teachers worry that added security detracts from learning.
The Parkland massacre a year ago upended school life in Florida. In the year since a gunman fatally shot 14 students and three school staffers, the state's districts have reshaped the K-12 experience, adopting new rules for entering campus, hiring more police and holding frequent safety drills. Some schools trained teams of armed employees to confront attackers.
"You can't really trust other students. They all have different mindsets," said Allen White, a senior at the lone high school in the central Florida farming town of Okeechobee.
Reflecting at a skate park near campus, White and four friends said their school's atmosphere changed after Feb. 14, 2018. Only last month, suspicious social media posts put Okeechobee High on alert, prompting many students, including White, to stay home.
"I don't really feel safe. It has become a real-life epidemic," he said. He attributed school violence primarily to bullying and mental health and said schools need to better address those issues.
Okeechobee is one of at least 24 Florida districts that have started training and arming non-instructional personnel.
On a recent afternoon, four school staffers met secretly at a grassy basin dug into the fertile land that borders Lake Okeechobee. They grabbed ammunition from a military-style container and loaded a handgun while standing by a picnic table. For hours, they practiced shooting at silhouette targets with sheriff deputies.
Authorities keep the identities of these "guardians" secret, citing security reasons. One of the women practicing said the 140 hours of required training adds to a busy schedule, but she feels compelled to do it just in case.
"Protecting the children's safety is first," she said. "They won't know that I am one of their guardians. But I will be prepared."
In Miami, parents say some schools — even preschools— have lost a sense of community since Parkland. Once-mundane morning drop-offs, for instance, have turned into a regimented affair.
Some schools previously allowed parents to drop off students directly with their teachers. Now children as young as 4 or 5 must be dropped off outside and walked inside by staff, cutting off opportunities for informal interaction with teachers.
"We are treated like we are criminals," said Karilyn Bacallao, a former teacher who now has two elementary school children. "The last time I heard the news it has never been the parent who comes to shoot."
Bacallao says she worries about how the new measures are affecting her 7-year-old daughter, who came home from class in tears one day in December.
"She starts telling me, 'There was blood in the bathroom, our teacher wasn't there, and there was a bad guy with a gun,'" she said.
Bacallao learned later that the school was on lockdown because of a nearby robbery. The kids were gathered in the cafeteria with a school counselor who turned the lights off and told them to draw in the dark. She said children heard sirens outside. Nobody explained the blood in the bathroom. Her daughter later found out it was nothing more than a nose bleed.
Teenagers are increasingly getting used to hearing about guns on campus.
Terezie Roberts is a member of Moms Demand Action, a nonprofit that fights to reform gun laws. She has two children in high school who now talk more about threats, but it is often unclear whether they are rumors or real.
"My son told me that he and his friends always talk and say that they could be the next" target. "It almost feels like a game to them," Roberts said.
Ivy Schamis, who was teaching Holocaust studies at Marjory Stoneman Douglas High School when her classroom came under attack, says more students now ask to visit the school's wellness center. The teacher whose classroom was across the hall from hers on the day of the shooting did not return to school this year, she said.
Schamis said it was "preposterous" that students have to come to school "thinking what may happen as opposed to what they are learning."
"It's absolutely disrupting education," she said.
A 2016 study published in the Educational Evaluation and Policy Analysis journal analyzed the effects of 36 high school shootings on math and English tests in 12 states over three years. It found that enrollment declined among 9th grade students, and test results dropped significantly when comparing those schools to others in the same district.
At the state Capitol, Florida Gov. Ron DeSantis and GOP state lawmakers want to expand the existing guardian program so more teachers can have guns. Senate Republicans filed the proposal last week.
Before the shooting, Schamis said, she would have "felt that only military and law enforcement should really carry guns." But now "I keep going over it in my head."
She shared the story of the school's athletic director, Chris Hixon, a Navy veteran who was shot in the legs as he ran toward suspect Nikolas Cruz.
"Had he had a gun, he might have been able to take the shooter down before any more damage was done. So now, I am not sure."